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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:47:55 +0000 |
commit | 2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4 (patch) | |
tree | 033cc839730fda84ff08db877037977be94e5e3a /vendor/hashbrown/src/macros.rs | |
parent | Initial commit. (diff) | |
download | cargo-2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4.tar.xz cargo-2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4.zip |
Adding upstream version 0.70.1+ds1.upstream/0.70.1+ds1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/hashbrown/src/macros.rs')
-rw-r--r-- | vendor/hashbrown/src/macros.rs | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/hashbrown/src/macros.rs b/vendor/hashbrown/src/macros.rs new file mode 100644 index 0000000..eaba6be --- /dev/null +++ b/vendor/hashbrown/src/macros.rs @@ -0,0 +1,70 @@ +// See the cfg-if crate. +#[allow(unused_macro_rules)] +macro_rules! cfg_if { + // match if/else chains with a final `else` + ($( + if #[cfg($($meta:meta),*)] { $($it:item)* } + ) else * else { + $($it2:item)* + }) => { + cfg_if! { + @__items + () ; + $( ( ($($meta),*) ($($it)*) ), )* + ( () ($($it2)*) ), + } + }; + + // match if/else chains lacking a final `else` + ( + if #[cfg($($i_met:meta),*)] { $($i_it:item)* } + $( + else if #[cfg($($e_met:meta),*)] { $($e_it:item)* } + )* + ) => { + cfg_if! { + @__items + () ; + ( ($($i_met),*) ($($i_it)*) ), + $( ( ($($e_met),*) ($($e_it)*) ), )* + ( () () ), + } + }; + + // Internal and recursive macro to emit all the items + // + // Collects all the negated cfgs in a list at the beginning and after the + // semicolon is all the remaining items + (@__items ($($not:meta,)*) ; ) => {}; + (@__items ($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => { + // Emit all items within one block, applying an appropriate #[cfg]. The + // #[cfg] will require all `$m` matchers specified and must also negate + // all previous matchers. + cfg_if! { @__apply cfg(all($($m,)* not(any($($not),*)))), $($it)* } + + // Recurse to emit all other items in `$rest`, and when we do so add all + // our `$m` matchers to the list of `$not` matchers as future emissions + // will have to negate everything we just matched as well. + cfg_if! { @__items ($($not,)* $($m,)*) ; $($rest)* } + }; + + // Internal macro to Apply a cfg attribute to a list of items + (@__apply $m:meta, $($it:item)*) => { + $(#[$m] $it)* + }; +} + +// Helper macro for specialization. This also helps avoid parse errors if the +// default fn syntax for specialization changes in the future. +#[cfg(feature = "nightly")] +macro_rules! default_fn { + (#[$($a:tt)*] $($tt:tt)*) => { + #[$($a)*] default $($tt)* + } +} +#[cfg(not(feature = "nightly"))] +macro_rules! default_fn { + ($($tt:tt)*) => { + $($tt)* + } +} |